Electrode for living body and device for detecting living signal

ABSTRACT

A biosignal measurement device includes an electrode and a signal processing member. The electrode includes an insulation sheet having a hole, a device contact portion provided on the top surface of the insulation sheet and a body contact portion provided on the bottom surface of the insulation sheet, the device contact portion and the body contact portion electrically connected to each other via the hole. The signal processing member includes an externally exposed terminal to make surface contact with the device contact portion, an analog signal processing unit, an A/D signal converter and a digital signal processing unit. Also, the device contact portion and the body contact portion are formed of a material which is both conductive and adhesive. Accordingly, the signal processing member may be directly attached. Noise may be reduced. Also, a biosignal may be accurately measured.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of prior application Ser. No.11/487,316, filed Jul. 17, 2006 in the U.S. Patent and Trademark Office,the disclosure of which is incorporated herein by reference. Thisapplication claims the priority benefit of prior application Ser. No.11/487,316. This application claims the priority benefit of KoreanPatent Application No. 10-2005-0099018, filed Oct. 20, 2005 and KoreanPatent Application No. 10-2006-0041143, filed May 8, 2006, in the KoreanIntellectual Property Office, the disclosures of which are incorporatedherein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an electrode for a living body, andmore particularly, to an electrode which can transmit an electricalsignal from a living body by using a simple electrode structure, and abiosignal measurement device using the electrode.

2. Description of Related Art

A living body is a kind of conductor and minute currents may occur inthe living body. Accordingly, internal properties of the living body maybe measured by sensing the minute currents from the living body anddetecting a change of the minute currents with respect to an externalstimulus. Generally, an electrocardiogram (ECG), an electromyogram(EMG), an electroencephalogram (EEG), a galvanic skin response (GSR), aneye electrooculogram (EOG), body temperature, pulse, blood pressure,body motion, etc. may be measured by using the above describedprinciple. An electrode for a living body is used for sensing a changeof a biosignal.

FIG. 1 is a perspective view illustrating a conventional electrode andbiosignal measurement device, and FIG. 2 is a cross-sectional viewillustrating an attachment state of the electrode of FIG. 1.

Referring to FIGS. 1 and 2, a conventional electrode 10 includes anadhesive sheet 20 and a metal electrode 30. The adhesive sheet 20 hasinsulating properties and is in the form of a round shape. The metalelectrode 30 makes direct contact with a living body. Also, the metalelectrode 30 is formed of a conductive material. The metal electrode 30includes a contact portion 32 widely provided on the bottom surface ofthe adhesive sheet 20 and a protrusion 34 formed on the center of thecontact portion 32. The protrusion 34 may be exposed to the outside ofthe adhesive sheet 20 via a hole. An adhesive material is formed on thebottom of the adhesive sheet 20. Accordingly, the electrode 10 may beclosely attached onto the skin of a body.

A biosignal measurement device 1 includes a main controller 40, theelectrode 10 and a cable 50. A socket 52 is provided at the end of thecable 52. A groove is formed in the socket 52 to be engaged with theprotrusion 34. Accordingly, the socket 52 and the metal electrode 30 maybe electrically connected to each other. The cable 50 may be connectedto the electrode 10 via the socket 52. Also, the cable 50 may beconnected to the main controller 40 via a plug provided opposite to thesocket 52. When the electrode 10 is attached onto a living body, themain controller 40 may measure a biosignal. Also, the main controller 40may measure an ECG, an EMG, an EEG, a GSR, an EOG, body temperature,etc. from the received biosignal.

Generally, the metal electrode 30 is directly exposed on the bottom ofthe electrode 10. While the adhesive sheet 20 is provided, a contactbetween the skin and the metal electrode 30 may not be stablymaintained. Accordingly, a gel-typed electrolyte is spread over theskin. By using the gel-typed electrolyte as a medium, a relativelystabilized connection state may be maintained between the skin and themetal electrode 30.

However, although the gel-typed electrolyte is used, the connectionusing the conventional electrode may be easily affected by some factorsthat may interfere with a stable connection. As an example, while abiosignal is being transmitted from the skin through a process ofskin-gel-metal electrode 30-socket 52-main controller 40, the biosignalmay be weakened or noise may be introduced. Also, the metal electrode 30and the socket 52 make point contact in the protrusion 34. Accordingly,an electrical connection state is very unstable. This can prevent anaccurate measurement.

An electrode in the conventional art is made to be expendable andgenerally disposable, so a user uses a new electrode every time. Sincefrequent attachments and detachments between the socket and theelectrode occur, unstable contact may often occur.

Also, a structure using the protrusion 34 and the socket 52 may bereferred to as a snap connecting structure. The snap connectingstructure is disadvantageous to miniaturize a biosignal measurementdevice. This is because the protrusion 34 is formed on the metalelectrode 30 and thus, the electrode 10 may not be flattened. Also,since the socket 52 for electric connection occupies a considerable areafor installation, the protrusions 34 of the electrode 30 should beseparated at the minimal interval needed for installation of the socket52, such that the electrode 30 may not be reduced.

Also, when integrating a plurality of electrodes onto a single body, aplurality of corresponding protrusions or snaps is required.Accordingly, the electrode or the device may not be easily miniaturized.

Also, when providing a plurality of snaps on a single body, an intervalbetween each snap needs to be identical to an interval between socketsto be properly connected with the snaps. When the interval between thesnaps is smaller than the interval between the sockets, the sockets maynot be installed on an electrode. Also, when the interval between thesnaps is larger than the interval between the terminals, connecting thesockets and snaps may cause the electrode to become deformed.

Accordingly, an electrode in a simple structure ensuring a stableconnection, and that can also be easily miniaturized, is required.

BRIEF SUMMARY

An aspect of the present invention provides an electrode and a biosignalmeasurement device which can stably maintain the connection between theelectrode and a cable.

An aspect of the present invention also provides an electrode and abiosignal measurement device having a simple structure which cantransmit a minute current and prevent noise.

An aspect of the present invention also provides an electrode and abiosignal measurement device which can simultaneously provide aplurality of electrodes on one pad and also can be miniaturized andslimmed down.

An aspect of the present invention also provides an electrode and abiosignal measurement device in which the electrode can be easilyinstalled on the device and replaced even when providing a plurality ofterminals on a single electrode.

An aspect of the present invention also provides an electrode and abiosignal measurement device which can be functionally advantageous evenwhen applied to a miniaturized device or a wearable device for measuringa biosignal.

According to an aspect of the present invention, there is provided anelectrode for living body, including a sheet member formed of aninsulating material and having a hole and an electrode member providedon the top and bottom surface of the sheet member via a hole. Theelectrode member includes a device contact portion making surfacecontact with a terminal of a biosignal measurement device on the topsurface of the sheet member and a body contact portion making contactwith the skin on the bottom surface of the sheet member. The devicecontact portion and the body contact portion are connected to each othervia the hole. Also, since the device contact portion is formed of aconductive material, the device contact portion may be electricallyconnected to the terminal of the biosignal measurement device. Minutecurrent transmitted from the skin is transferred via a simple pathconsisting of the electrode member and the terminal. In this case, theelectrode member and the terminal are connected to each other by notpoint contact but surface contact. Accordingly, a signal-to-noise (S/N)ratio may be improved.

The device contact portion and the body contact portion may be formed ofa material which is both conductive and adhesive. Also, the devicecontact portion and the body contact portion may be formed by molding ahydrogel in both surfaces of the sheet member. Unlike the conventionalelectrode transmitting an electrical signal by point contact between aprotrusion and a receiving portion, the electrode according to an aspectof the present invention may transmit an electrical signal by surfacecontact between the device contact portion and the terminal. Also,hydrogel itself has adhesive properties. Accordingly, the terminal orthe biosignal measurement device may be attached onto the electrodewithout using a protrusion or snap.

A conventional electrode generally has to include a protrusion and areceiving portion. Accordingly, there is a limit in miniaturizing theelectrode. However, according to various aspects of the presentinvention, it is possible to make a device contact portion and a bodycontact portion in various sizes and in various shapes. Also, the deviceand body contact portions may be formed in the shape of a flat board.Accordingly, a thickness thereof may be significantly reduced. Also, asignal transmission process from the skin to a circuit may besimplified. Accordingly, motion artifacts may be reduced.

According to another aspect of the present invention, there is provideda biosignal measurement device which can provide a plurality ofelectrode members on a single insulation sheet. Namely, at least onetype of data may be measured via the single electrode by forming aplurality of holes in the sheet member and connecting a device contactportion and a body contact portion via each hole. In this instance, thedevice contact portion and the body contact portion, which areone-to-one connected to each other via the each hole, need to beelectrically separated from other device contact portions and other bodycontact portions, but may be electrically connected to another devicecontact portion or body contact portion which is connected via anotherhole.

According to another aspect of the present invention, there is provideda biosignal measurement device using the above-described electrode. Thebiosignal measurement device may include a signal processing member andan electrode member.

The signal processing member includes a plurality of externally exposedterminals, an analog signal processing unit, an analog-to-digital (A/D)signal converter for converting an analog signal into a digital signaland a digital signal processing unit for processing the converteddigital signal. The electrode member includes an insulation sheet havinga plurality of holes, a plurality of device contact portions formed inthe shape of a flat board on the top surface of the insulation sheet andinsulated from each other, and a plurality of body contact portionsformed in the shape of a flat board on the bottom surface of theinsulation sheet insulated from each other and individually connected toeach device contact portion via the hole. In this instance, the devicecontact portion and the body contact portion may be formed of a materialwhich is both conductive and adhesive and is electrically connected to aterminal. Also, the device contact portion and the body contact portionmay maintain an attachment state without using a protrusion.

According to another aspect of the present invention, a biosignalmeasurement device may electrically connect a bottom surface and a topsurface of an electrode without forming a hole. For this, the electrodeincludes two types of insulation sheets so that the two types ofinsulation sheets may cover and expose a top surface and a bottomsurface of an electrode member.

As an example, the electrode may include a first insulation sheet, atleast one electrode member that is provided on the first insulationsheet, and a second insulation sheet that is provided on the electrodemember. The electrode member is formed in the shape of a flat board on atop surface of the first insulation sheet, of which one end is formed onthe first insulation sheet and another end is externally exposed awayfrom the first insulation sheet. Since the electrode member is formed ofa material which is both conductive and adhesive, the electrode membermay temporarily maintain its attachment state to a device or a body. Thesecond insulation sheet provided on the electrode member may be formedexposing the top surface of the one end of the electrode member andelectrically isolating the top surface of the other end of the electrodemember. When at least two electrode members are provided on the singleinsulation sheet, the electrode members may be arranged in an identicaldirection or in a different direction. According to the arrangement ofthe electrode member, the second insulation sheet may cover a portion ofthe top surface of the electrode member in an integrated form or in aseparated form.

According to another aspect of the present invention, a biosignalmeasurement device may use a snap connected terminal in a gender shapetogether with a flat board connected terminal utilizing surface contact.Namely, when connecting a signal processing member and an electrodemember, the two members may be electrically and mechanically connectedto each other using the snap connected terminal. Also, the flat boardconnected terminal may be connected by a flat board connecting structureusing surface contact. Accordingly, it may be possible to prevent theelectrode member from bending due to an alignment error between theterminals. Also, since an initial attachment location between the signalprocessing member and the electrode member may be easily found using thesnap connected terminal which is comparatively excellent in a mechanicalconnection, the signal processing member and the electrode member may bemore securely combined with each other.

As an example, the signal processing member may include an externallyexposed snap terminal and a flat board terminal adjacent to the snapterminal. Also, the electrode member may include an insulation sheet, asnap contact portion electrically and mechanically connected to the snapterminal on a top surface of the insulation sheet, a flat board contactportion electrically connected to the flat board terminal and formed ofa material which is both conductive and adhesive, a first body contactportion electrically connected to the snap contact portion on a bottomsurface of the insulation sheet, and a second body contact portionelectrically connected to the flat board contact portion on the bottomsurface of the insulation sheet. The snap contact portion and the firstbody contact portion of the electrode member may form a snap electrodemember. Also, the flat board contact portion and the second body contactportion may form a flat board electrode member which is insulated fromthe snap contact member.

As described above, the snap contact portion and the first body contactportion of the snap electrode member may be electrically connected toeach other at a hole formed on the insulation sheet. Also, the snapcontact portion and the first body contact portion may be electricallyconnected to each other by surrounding the insulation sheet. Also, theflat board contact portion and the second body contact portion of theflat board electrode member may be connected to each other by theabove-described method or other methods.

The snap contact portion may rotate when the snap contact portion iselectrically connected to the snap terminal. A user may adjust aposition using an inserted snap contact portion as an axis, so thatother flat board contact portions or snap contact portions may beadjacent to a corresponding flat board terminal or snap terminal.

Also, the snap contact portion and the snap terminal may have anoncircular section, e.g. an oval and a polygon, to prevent rotation.When the user inserts a standard snap contact portion into a snapterminal corresponding to the standard snap contact portion, the usermay complete the adjustment of the position.

Any one of the snap contact portion and the snap terminal may be aprotrusion. In this case, the snap contact portion and the snap terminalmay be mechanically combined with each other by elasticity or aself-force.

Additional and/or other aspects and advantages of the present inventionwill be set forth in part in the description which follows and, in part,will be obvious from the description, or may be learned by practice ofthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and/or other aspects and advantages of the present inventionwill become apparent and more readily appreciated from the followingdetailed description, taken in conjunction with the accompanyingdrawings of which:

FIG. 1 is a perspective view illustrating a conventional electrode andbiosignal measurement device;

FIG. 2 is a cross-sectional view illustrating an attachment state of theelectrode in FIG. 1;

FIG. 3 is a perspective view illustrating an electrode and a biosignalmeasurement device according to an embodiment of the present invention;

FIG. 4 is a cross-sectional view illustrating the electrode and thebiosignal measurement device of FIG. 3;

FIG. 5 is a diagram illustrating a function of a signal processing unitof FIG. 3;

FIG. 6 is a partial cross-sectional view illustrating a biosignalmeasurement device and an electrode according to another embodiment ofthe present invention;

FIG. 7 is a cross-sectional view illustrating a biosignal measurementdevice and an electrode according to still another embodiment of thepresent invention;

FIG. 8 is a top view illustrating the electrode and the biosignalmeasurement device of FIG. 7;

FIG. 9 is a cross-sectional view illustrating a biosignal measurementdevice and an electrode according to an embodiment of the presentinvention;

FIG. 10 is a top view illustrating the electrode of FIG. 9;

FIG. 11 is a cross-sectional view illustrating an electrode and abiosignal measurement device according to an embodiment of the presentinvention;

FIG. 12 is a top view illustrating an electrode and a biosignalmeasurement device according to another embodiment of the presentinvention; and

FIG. 13 is a top view illustrating an electrode and a biosignalmeasurement device according to still another embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to embodiments of the presentinvention, examples of which are illustrated in the accompanyingdrawings, wherein like reference numerals refer to the like elementsthroughout. The embodiments are described below in order to explain thepresent invention by referring to the figures.

FIG. 3 is a perspective view illustrating an electrode and a biosignalmeasurement device according to an embodiment of the present invention,and FIG. 4 is a cross-sectional view illustrating the electrode and thebiosignal measurement device of FIG. 3.

Referring to FIGS. 3 and 4, a biosignal measurement device 100 includesa signal processing unit 110 and an electrode 200. The electrode 200 isattached onto a living body for measurement of biosignals and the signalprocessing unit 110 is placed on the electrode 200. An electrolysiscream including an electrolyte may be used for attaching the electrode200 onto the living body. After spreading the electrolysis cream overthe skin, the electrode 200 may be attached thereto. Also, the signalprocessing unit 110 is placed on the electrode 200. In this instance, aterminal 115 of the signal processing unit 110 is electrically connectedto the electrode 200. The terminal 115 and the electrode 200 makesurface contact by using their flat contact surfaces. Accordingly, theterminal 115 and the electrode 200 have the wide contact area. Also,since a wide surface is used, resistance may be reduced. Accordingly, aminute current in a living body may be effectively transmitted to theterminal 115 of the signal processing unit 110.

The electrode 200 includes an insulation sheet 210 and an electrodemember 220.

The insulation sheet 210 is formed of a nonconductive or insulatingmaterial. Also, the insulation sheet 210 may be provided by using paperor insulating resin. The insulation sheet 210 is formed in the shape ofa circle or a polygon. A hole 212 is formed in the center of theinsulation sheet 210. The hole 212 may integrally connect portions ofthe electrode member 220. In this instance, each portion is provided onthe top and bottom surfaces of the insulation sheet 210. The electrodemember 220 includes a device contact portion 222 and a body contactportion 224, which are connected to each other via the hole 212.

In the present embodiment, one hole 212 is formed in one insulationsheet 210 and one electrode member 220 is provided. However, to collectvarious types of information at the same time, one electrode may measurechanges with respect to various points. In this case, a plurality ofholes is formed in one insulation sheet. The electrode member 220corresponding to each hole may be individually provided. Also, a signalprocessing unit may include a plurality of terminals. In this case, eachterminal may maintain a one-to-one relationship with each correspondingdevice contact portion and may be electrically connected thereto.

Referring again to FIGS. 3 and 4, the device contact portion 222 and thebody contact portion 224 of the electrode member 220 are formed of amaterial which is both conductive and adhesive. The electrode member 220may transmit a minute current from a living body to the signalprocessing unit 110. Also, since the device contact portion 222 hasadhesive properties, the device contact portion 222 may be attached tothe bottom surface of the signal processing unit 110. Although acombinational relationship between a protrusion and a groove as in theconventional art is not formed, adhesiveness may be effectivelymaintained. A material having conductive and adhesive properties may bevariously selected, but a hydrogel is usually utilized.

The device contact portion 222 and the body contact portion 224 areintegrally formed as a single body. This may be manufactured by moldinga melted or fluidic hydrogel in both surfaces of the insulation sheet210. More specifically, the device contact portion 222 and the bodycontact portion 224 may be provided by placing a fluidic hydrogel aroundthe hole 212 and molding the fluidic hydrogel into a solid materialwhich is both conductive and adhesive.

The insulation sheet 210 and the electrode member 220 may be flexiblytransformable and easily attached onto an attachment area while takingon a shape of an attachment area. Also, to easily attach the electrode200 onto a living body, an adhesive material may be placed around theinsulation sheet 210 adjacent to the body contact portion 224.

The terminal 115 in the form of a metal may be exposed on the bottomsurface of the signal processing unit 110. The signal processing unit110 may be provided on the electrode 200 by placing the bottom surfaceof the signal processing unit 100 on the top surface of the devicecontact portion 222. In this case, the terminal 115 and the devicecontact portion 222 are closely attached to each other by surfacecontact. Accordingly, the terminal 115 and the device contact portion222 may be electrically connected to each other via the wide surface.Through this, transmissibility between the device contact portion 222and the terminal 115 may be improved. Also, a signal-to-noise (S/N)ratio may be improved.

Also, since the device contact portion 222 has adhesive properties, thedevice contact portion 222 may maintain a combined state with the signalprocessing unit 110 without using a combinational structure. The signalprocessing unit 110 may be connected to an external device in a wired orwireless manner. Also, while being attached onto a living body, thesignal processing unit 110 may transmit biosignal data, such as an ECG,an EMG, an EEG, a GSR, etc., of a subject. In the conventional art, acombinational structure using a protrusion and a groove was used forattaching a signal processing unit to an electrode. However, in thepresent embodiment, the device contact portion 222 maintains a combinedstate by using adhesive properties of a hydrogel.

Referring to FIG. 4, the device contact portion 222 and the body contactportion 224 are connected via the hole 212. Structurally, the devicecontact portion 222 and the body contact portion 224 are electricallyconnected to each other via a hole connector 226 corresponding to thehole 212.

FIG. 5 is a diagram illustrating a function of a signal processing unitof FIG. 3.

Referring to FIG. 5, the signal processing unit 110 includes an analogsignal processing unit 120, an A/D converter 130, a digital signalprocessing unit 140 and a wireless transmission module 150, which aresequentially provided from the terminal 115. The analog signalprocessing unit 120 may amplify or filter a minute current of a livingbody transmitted from the terminal 115, that is, an analog signal andtransmit the same to the A/D converter 130. The A/D converter 130converts the transmitted analog signal into a digital signal. Thedigital signal processing unit 140 processes the converted digitalsignal according to a programmed method. Process results may betransmitted to an external device via the wireless transmission module150 or may be stored in an internal memory (not illustrated).

FIG. 6 is a partial cross-sectional view illustrating a biosignalmeasurement device and an electrode according to another embodiment ofthe present invention.

In this instance, a signal processing unit 110 and an electrode 201 ofFIG. 6 are similar to the signal processing unit 110 and the electrode200 of FIG. 5. The only difference is that the electrode 201 of FIG. 6further includes device holders 230.

Referring to FIG. 6, the device holders 230 are provided on or aroundthe device contact portion 222 to receive the edge of a lower portion ofthe signal processing unit 110. Accordingly, after placing the signalprocessing unit 110 on the device contact portion 222, the movement ofthe signal processing unit 110 may be limited by the device holders 230.Namely, the device holders 230 prevent the placed signal processing unit110 from being easily separated from the electrode 201. Also, the deviceholder 230 is formed of a nonconductive material. Accordingly, thedevice holder 230 has insulating properties. Also, the device holder 230may be formed of soft rubber or foam. Accordingly, the device holder 230may produce friction for holding the signal processing unit 110.

In the present embodiment, the signal processing unit 110 is connectedto an external device via a cable. Results processed by a digital signalprocessing unit may be transmitted to an external device via the cable.

FIG. 7 is a cross-sectional view illustrating a biosignal measurementdevice and an electrode according to still another embodiment of thepresent invention, and FIG. 8 is a top view illustrating the electrodeand the biosignal measurement device of FIG. 7.

Referring to FIGS. 7 and 8, a biosignal measurement device 300 includesa signal processing unit 310 and an electrode 400. The electrode 400 isattached onto a living body for measurement of biosignals and the signalprocessing unit 310 is placed on the electrode 400. An electrolysiscream including an electrolyte may be used for attaching the electrode400 onto the living body. In this instance, three terminals 315 of thesignal processing unit 310 are placed on the electrode 400. Eachterminal 315 of the signal processing unit 310 is electrically connectedto the electrode 400. Each terminal 315 and the electrode 400 makesurface contact by using their flat contact surfaces. Accordingly, theterminal 315 and the electrode 400 have a wide contact area. Also, sincea wide surface is used, resistance may be reduced. Accordingly, a minutecurrent in a living body may be effectively transmitted to the terminal315 of the signal processing unit 310.

The electrode 400 includes an insulation sheet 410 and electrode members420, 430 and 440. The insulation sheet 410 is formed of a nonconductiveor insulating material. Also, the insulation sheet 410 may be providedby using paper or insulating resin. The insulation sheet 410 is extendedin the shape of a band. Three electrode members 420, 430 and 440 areprovided side by side in the insulation sheet 410. In this instance,three holes 412, each shaped as a rectangle, are formed in thelengthwise direction of the insulation sheet 410. The holes 412 are tointegrally connect portions of the electrode member 420. In thisinstance, each portion is provided on the top and bottom surfaces of theinsulation sheet 410. Each of the electrode members 420, 430 and 440includes each corresponding portion of device contact portions 422, 432and 442 and body contact portions 424, 434 and 444, which areelectrically connected to each other via each of the holes 412.

When the electrode member 420 is provided in the left side of theinsulation sheet 410, the device contact portion 422 and the bodycontact portion 424 are connected via the hole connector 426. In thiscase, the hole connector 426 is formed in the hole 412. The devicecontact portion 422 and the body contact portion 424 constructing theelectrode member 420 are electrically connected to each other via thehole connector 426 by using a material which is both conductive andadhesive, such as a hydrogel. The electrode member 420 senses abiosignal from an area corresponding to the left side of the insulationsheet 410. The electrode member 440 provided in the right side of theinsulation sheet 410 has a symmetrical structure to the electrode member420 provided in the left side thereof.

The electrode member 430 is provided in the center of the insulationsheet 410. Also, the electrode member 430 includes the device contactportion 432 and the body contact portion 434, which are electricallyconnected to each other via the hole connector 436.

Referring to FIG. 7, the device contact portion 422 and the body contactportion 424 of the electrode member 420 are provided diagonal to eachother. In this instance the device contact portion 422 and the bodycontact portion 424 are electrically connected to each other via thehole 412.

A device contact portion and a body contact portion may be provided tohave the same center or diagonal to each other in upper and lowerportions of an electrode member. For example, the device contact portion432 and the body contact portion 434 of the central electrode member 430are vertically positioned to have the same center, however the devicecontact portion 422 and the body contact portion 424 of the centralelectrode member 420 are divergently positioned to have the differentcenter.

Also, a device contact portion and a body contact portion may have adifferent area in upper and lower portions of an electrode member.Accordingly, irrespective of a position and an interval of the bodycontact portions 424, 434 and 444, a position of the device contactportions 422, 432 and 442 may be changed. Also, the device contactportions 422, 432 and 442 may be centralized in a desired area. Whencentralizing the device contact portions 422, 432 and 442, the signalprocessing unit 310 may be made in a small size. Accordingly, thebiosignal measurement device may be further miniaturized.

The electrode members 420, 430 and 440 may sense a biosignal from eachcorresponding area and transmit the biosignal to the signal processingunit 310. Also, because of the adhesive properties, the device contactportions 422, 432 and 442 may be attached onto the bottom surface of thesignal processing unit 310 and maintain effective adhesiveness. Amaterial having conductive and adhesive properties may be variouslyselected, but a hydrogel is usually utilized.

As illustrated in FIG. 7, the insulation members 452 may be providedaround the device contact portion 422, 432 and 442. In this case, eachof the insulation members 452 has the same or less thickness as one ofthe adjacent device contact portion 422, 432, and 442. Also, theinsulation members 452 may support the bottom surface of the signalprocessing unit 310 together with the device contact portions 422, 432and 442. The insulation member 452 may be formed of a material which isnonconductive and adhesive. Accordingly, the insulation members 452 mayinsulate the device contact portions 422, 432 and 442, because ofnonconductive properties. Also, the insulation members 452 may beattached onto the signal processing unit 310 with the device contactportions 422, 432 and 442, because of adhesive properties.

A contact portion or an adhesive agent having insulating properties maybe provided on the bottom surface of the insulation sheet 410 and aroundthe body contact portions 424, 434 and 444. In the present embodiment,an insulation attaching member 454 is provided. The insulation attachingmember 454 may attach the electrode 400 to the skin with the bodycontact portions 424, 434 and 444.

The terminals 315 in the form of a metal are provided side by side onthe bottom surface of the signal processing unit 310. The bottom surfaceof the signal processing unit 310 is placed on the device contactportions 422, 432 and 442. In this manner, the signal processing unit310 may be placed on the electrode 400 and each terminal 315 and each ofthe corresponding device contact portions 422, 432 and 442 make surfacecontact with each other. Namely, each terminal 315 and each of thecorresponding device contact portions 422, 432 and 442 are electricallyconnected to each other by a large surface area. Accordingly, theterminal 315 and the corresponding device contact portion 422, 432 and442 may be electrically connected to each other. Also, the devicecontact portions 422, 432 and 442 are insulated from each other, so anindividual connection between the terminal 315 and one of thecorresponding device contact portion 422, 432 and 442 may be maintained.Through this, transmissibility between the corresponding device contactportion 422, 432 and 442 and the terminal 315 may be improved. Also, asignal-to-noise (S/N) ratio may be improved.

Also, the device contact portions 422, 432 and 442 have adhesiveproperties. Accordingly, the device contact portions 442, 432 and 442may maintain a combined state with the signal processing unit 310 whilenot having a combination structure. The signal processing unit 310 maybe connected to an external device in a wired or wireless manner. Also,while being attached onto a living body, the signal processing unit 310may transmit biosignal data of a subject, such as an ECG, an EMG, anEEG, a GSR, etc. In the conventional art, a combinational structureusing a protrusion and a groove is used for attaching a signalprocessing unit onto an electrode. However, in the present embodiment,the device contact portions 422, 432 and 442 maintain a combined stateby using adhesive properties of a hydrogel.

The signal processing unit 310 includes an analog signal processingunit, an A/D converter, a digital signal processing unit and a wirelesstransmission module, which are sequentially provided from the terminal315. The analog signal processing unit receives a biosignal from threeterminals and transmits the biosignal to the A/D converter afteramplification or filtering. The A/D converter converts the transmittedanalog signal into a digital signal. The digital signal processing unitprocesses the converted digital signal according to a programmed method.Process results may be transmitted to an external device via thewireless transmission module.

The device holders 460 are provided on or around the device contactportions 422 and 442 to receive the edge of a lower portion of thesignal processing unit 310. Accordingly, after placing the signalprocessing unit 310 on the device contact portions 422, 432 and 442, thesignal processing unit 310 may be more securely held by the deviceholders 460. Also, the device holder 460 is formed of a nonconductivematerial. Accordingly, the device holder 460 has insulating properties.Also, the device holder 460 may be formed of soft rubber or foam.Accordingly, the device holder 460 may produce friction for holding thesignal processing unit 310.

In the present embodiment, the signal processing unit 310 is connectedto an external device via a cable. Results processed by a digital signalprocessing unit may be transmitted to the external device via the cable.

FIG. 9 is a cross-sectional view illustrating a biosignal measurementdevice and an electrode according to an embodiment of the presentinvention, and FIG. 10 is a top view illustrating the electrode of FIG.9.

Referring to FIGS. 9 and 10, a biosignal measurement device 500 includesa signal processing unit 510 and an electrode 600. The electrode 600 isattached onto a living body for measurement of biosignals and the signalprocessing unit 510 is placed on the electrode 600. Also, two terminals515 of the signal processing unit 510 are placed on the electrode 600.Each terminal 515 of the signal processing unit 510 is electricallyconnected to the electrode 600. Each terminal 515 and the electrode 600make surface contact by using their flat contact surfaces. Also, since awide surface is used, resistance may be reduced.

The electrode 600 includes an insulation sheet 610 and electrode members620 and 630. The insulation sheet 610 is formed of a nonconductive orinsulating material. Also, the insulation sheet 610 may be provided byusing paper or insulating resin. Two electrode members 620 and 630 areprovided on opposite sides of the insulation sheet 610 and partiallylaid on its top surface. The electrode members 620 and 630 are juttedout and externally exposed from both ends of the insulation sheet 610.Also, other insulation sheets 660 are provided on a top surface of theelectrode members 620 and 630.

Unlike the above-described embodiments, the insulation sheet 610 has nohole. The electrode members 620 and 630 may have a body contact portionand a device contact portion, respectively. The body contact portion ofthem may be an outside portion externally exposed from a bottom surfaceof the insulation sheet 610 and facing downward, and the device contactportion of them may be an inside portion internally exposed portion fromthe insulation sheet 660 and facing upward.

Since both the electrode members 620 and 630 are formed of a materialwhich is conductive and adhesive, such as a hydrogel, the electrode 600may be attached onto a living body. Also, since the device contactportions of the electrode member 620 and 630 are centrally gathered, thesize of the signal processing unit 510 may be reduced. Also, the size ofthe biosignal measurement device 500 may be further reduced.

The electrode members 620 and 630 may sense a biosignal from eachcorresponding area and transmit the biosignal to the signal processingunit 510. Also, because of the adhesive properties of the electrodemembers 620 and 630, the signal processing unit 510 may be attached tothe device contact portions of them.

Also, an adhesive material 652 is provided on the bottom surface of theinsulation sheet 610 to improve adhesive strength between the electrode600 and a living body and another adhesive material 654 is providedbetween the electrode members 620 and 630 to improve adhesive strengthbetween the electrode 600 and the signal processing unit 510.

The two metal terminals 515 are closely provided on the bottom surfaceof the signal processing unit 510 and insulated from each other. Thebottom surface of the signal processing unit 510 is placed on the devicecontact portion of the electrode members 620 and 630. In this manner,the signal processing unit 510 may be placed on the electrode 600 andeach terminal 515 and each corresponding device contact portion makesurface contact with each other.

The signal processing unit 510 includes an analog signal processingunit, an A/D converter, a digital signal processing unit and a wirelesstransmission module, which are sequentially provided from the terminal515. The analog signal processing unit receives a biosignal from threeterminals and transmits the biosignal to the A/D converter afteramplification or filtering. The A/D converter converts the transmittedanalog signal into a digital signal. The digital signal processing unitprocesses the converted digital signal according to a programmed method.Process results may be transmitted to an external device via thewireless transmission module.

FIG. 11 is a cross-sectional view illustrating an electrode and abiosignal measurement device according to an embodiment of the presentinvention.

Referring to FIG. 11, a biosignal measurement device 700 includes asignal processing unit 710 and an electrode 800. The electrode 800 isattached onto a living body for measurement of biosignals and the signalprocessing unit 710 is placed on the electrode 800 and may process ortransmit information from the electrode 800.

A snap terminal 720 and a flat board terminal 730 are provided on abottom surface of the signal processing unit 710. The snap terminal 720corresponds to a snap contact portion 822 of the electrode 800 toreceive the snap contact portion 822 and be electrically andmechanically connected thereto. The flat board terminal 730 correspondsto a flat board contact portion 832 of the electrode 800 and may beelectrically connected to the flat board contact portion 832. As shownin FIG. 11, the snap contact portion 822 is a protrusion and the snapterminal 720 is formed as a groove to receive and fix the snap contactportion 822. Also, a projection is formed in a lower portion of the snapterminal 720 and a groove is formed in a lower portion of the snapcontact portion 822. Accordingly, the snap terminal 720 and the snapcontact portion 822 may maintain a secure combination state.

In the present embodiment, the snap terminal 720 and the snap contactportion 822 are mechanically combined with each other by physicalengagement using elasticity. However, the snap terminal 720 and the snapcontact portion 822 may be mechanically combined with each other usingmagnetism and a magnetic substance.

The flat board terminal 730 is provided on a bottom surface of thesignal processing unit 710. The flat board contact portion 832corresponding to the flat board terminal 730 is provided on a topsurface of the electrode 800. The flat board contact portion 832 isformed of a material which is both conductive and adhesive, e.g. ahydrogel, and may maintain its electrical connection state with the flatboard terminal 730. The adhesive property of the flat board contactportion 832 may prevent the flat board terminal 730 from becomingseparated. Also, the adjacent snap contact portion 822 maintains a morestable combination state with the snap terminal 720. Accordingly, thesignal processing unit 710 and the electrode 800 may maintain a stableattachment state.

Also, a combination location between the signal processing unit 710 andthe electrode 800 may be easily determined by the snap terminal 720 andthe snap contact portion 822 which are the protrusion and the groove,respectively. Accordingly, a user may initially insert the snap terminal720 into the snap contact portion 822 and stably attach the signalprocessing unit 710 and the electrode 800.

When connecting a plurality of terminals using a snap connectingstructure, a combination between the terminals may be difficult or anelectrode may be misaligned due to a manufacturing defect. However, asignal processing unit and an electrode may be stably attached bytolerating a certain amount of error when using the snap connectingstructure together with a flat board connecting structure.

The electrode 800 includes an insulation sheet 810, the snap contactportion 822 and the flat board contact portion 832 on the top surface ofthe insulation sheet 810, and a first body contact portion 824 and asecond body contact portion 834 on the bottom surface of the insulationsheet 810. The snap contact portion 822 and the first body contactportion 824 may be electrically connected to each other via a hole onthe insulation sheet 810. Also, the flat board contact portion 832 andthe second body contact portion 834 may be electrically connected toeach other via another hole on the insulation sheet 810.

The snap contact portion 822 and the first body contact portion 824 maybe formed of a metal and form a single snap electrode member 820. Also,the flat board contact portion 832 and the second body contact portion834 may be formed of a hydrogel and form a single flat board electrodemember 830. Also, the snap contact portion 822 and the first bodycontact portion 824 may be formed of different materials. Also, the flatboard contact portion 832 and the second body contact portion 834 may beformed of different materials.

Although not illustrated, the signal processing unit 710 may include ananalog signal processing unit, an A/D converter, a digital signalprocessing unit and a wireless transmission module, which aresequentially provided from the terminal 720. The analog signalprocessing unit may receive a biosignal from the terminals 720 and 730and transmit the biosignal to the A/D converter after amplification orfiltering. The A/D converter may convert the transmitted analog signalinto a digital signal. The digital signal processing unit may processthe converted digital signal according to a programmed method. Processresults may be transmitted to an external device via the wired/wirelesstransmission module.

FIG. 12 is a top view illustrating an electrode 800 and a biosignalmeasurement device according to another embodiment of the presentinvention, and FIG. 13 is a top view illustrating an electrode 800 and abiosignal measurement device according to still another embodiment ofthe present invention.

In FIGS. 12 and 13, a signal processing unit 710 and an electrode 800are separated from each other on the left and the signal processing unitand the electrode are combined with each other on the right.

Referring to FIG. 12, a snap terminal 720 and a snap contact portion 822may have a circular section. Since a portion of the snap contact portion822, connected to the signal processing unit 710, has the circularsection, the signal processing unit 710 may rotate on the snap contactportion 822. Accordingly, a user may initially combine the snap terminal720 with the snap contact portion 822 and rotate the signal processingunit 710, so that the flat board terminal 730 and the flat board contactportion 832 may be connected to each other in an appropriate position.

However, referring to FIG. 13, a signal processing unit 710′ and anelectrode 800′ may be properly attached in only a certain position. Forthis, a snap terminal 720′ and a snap contact portion 822′ may have anoncircular shape, e.g. an oval, a square and a pentagon. Since aportion of the snap contact portion 822′ connected to the signalprocessing unit 710′ has a noncircular section, the signal processingunit 710′ may be inserted into the snap contact portion 822′ in only thecertain direction. In this case, the signal processing unit 710′ may notrotate on the snap contact portion 822′. Accordingly, the user mayattach the signal processing unit 710′ and the electrode 800 in anappropriate position by combining the snap terminal 720′ and the snapcontact portion 822′ in a proper position.

An electrode according to the above-described embodiments of the presentinvention may maintain a stable connection with a terminal or a signalprocessing unit. Also, the electrode may make surface contact with theterminal or the signal processing unit. Accordingly, a minute currentmay be smoothly transmitted from a living body to the electrode. Also,since a stable connection is maintained, noise is reduced and asignal-to-noise (S/N) ratio may be improved.

Also, according to the above-described embodiments of the presentinvention, a plurality of electrodes may be provided on one pad. Aposition, size and shape of a contact portion may be arbitrarilydetermined. Accordingly, a miniaturized and slimmed down product may bemanufactured.

Also, a biosignal measurement device according to the above-describedembodiments of the present invention may utilize advantages of both asnap connected terminal and a flat board connected terminal by using thesnap connected terminal together with the flat board connected terminalusing surface contact. Namely, when connecting a signal processingmember and an electrode member, the two members may be electrically andmechanically connected to each other using the snap connected terminal.Also, the flat board connected terminal may be connected by a flat boardconnecting structure using surface contact. Accordingly, it may bepossible to prevent the electrode member from bending due to an intervalerror between the terminals.

Also, according to the above-described embodiments of the presentinvention, an initial attachment location between the signal processingmember and the electrode member may be easily found using the snapconnected terminal which is comparatively superior in a mechanicalconnection, and the signal processing member and the electrode membermay be more securely combined with each other.

Although a few embodiments of the present invention have been shown anddescribed, the present invention is not limited to the describedembodiments. Instead, it would be appreciated by those skilled in theart that changes may be made to these embodiments without departing fromthe principles and spirit of the invention, the scope of which isdefined by the claims and their equivalents.

1. An electrode for transmission between a biosignal measurement deviceand a living body, comprising: a sheet member formed of an insulatingmaterial and having a hole; and an electrode member formed of aconductive material and including a device contact portion on a topsurface of the sheet member and making surface contact with a terminalof the biosignal measurement device and a body contact portion on abottom surface of the sheet member, the device contact portion and thebody contact portion electrically connected to each other at the hole.2. The electrode of claim 1, wherein the electrode member is formed of amaterial which is both conductive and adhesive.
 3. The electrode ofclaim 2, wherein the electrode member is provided by placing a material,which is both fluidic conductive and adhesive, around the hole of thesheet member and molding the fluidic conductive and adhesive materialinto a solid material which is both conductive and adhesive.
 4. Theelectrode of claim 1, wherein an adhesive material is applied around thebody contact portion on the bottom surface of the sheet member.
 5. Theelectrode of claim 1, wherein an insulation member is provided aroundthe device contact portion to make surface contact with the biosignalmeasurement device, and the insulation member is formed of a materialwhich is both nonconductive and adhesive.
 6. The electrode of claim 1,further comprising: a device holder formed of a nonconductive materialand holding an edge of a body or a terminal of the biosignal measurementdevice on the top surface of the sheet member.
 7. An electrode fortransmission between a biosignal measurement device and a living body,comprising: an insulation sheet having a plurality of holes; and aplurality of electrode members each formed of a material which is bothconductive and adhesive and being insulated from each other, each of theelectrode members including a device contact portion in a shape of aflat board on a top surface of the insulation sheet, a body contactportion in a shape of a flat board on a bottom surface of the insulationsheet, and a hole connector connecting the device contact portion andthe body contact portion of each electrode member at respective ones ofthe holes.
 8. The electrode of claim 7, wherein a material, which isboth nonconductive and adhesive, is around the device contact portionand the body contact portion of the insulation sheet.
 9. The electrodeof claim 7, wherein insulation members are provided around the devicecontact portion and the body contact portion, the insulation members areformed of a material which is both nonconductive and adhesive, and eachof the insulation members a thickness less than or equal to one of anadjacent device contact portion and an adjacent body contact portion.10. The electrode of claim 7, further comprising: a device holder formedof a nonconductive material and holding an edge of a body or a terminalof the biosignal measurement device on the top surface of the insulationsheet.
 11. A biosignal measurement device for making contact with aliving body and measuring a biosignal, comprising: a signal processingmember comprising an externally exposed terminal, an analog signalprocessing unit processing an analog signal transmitted from theterminal, an analog-to-digital (A/D) signal converter converting theanalog signal into a digital signal, and a digital signal processingunit processing the converted digital signal; and an electrode membercomprising an insulation sheet having a hole, a device contact portionon a top surface of the insulation sheet to make surface contact withthe terminal of the signal processing member and a body contact portionon a bottom surface of the insulation sheet and electrically connectedwith the device contact portion, the device contact portion and the bodycontact portion formed of a conductive material, wherein an insulationmember is provided around the device contact portion to make surfacecontact with the signal processing member, and the insulation member isformed of a material which is both nonconductive and adhesive.
 12. Abiosignal measurement device for making contact with a living body andmeasuring a biosignal, comprising: a signal processing member comprisinga plurality of externally exposed terminals, an analog signal processingunit processing an analog signal transmitted from the plurality ofterminals, an analog-to-digital (A/D) signal converter converting theanalog signal into a digital signal, and a digital signal processingunit processing the converted digital signal; and an electrode membercomprising an insulation sheet having a plurality of holes, a pluralityof device contact portions each formed in a shape of a flat board on atop surface of the insulation sheet and insulated from each other and aplurality of body contact portions in a shape of a flat board on abottom surface of the insulation sheet, insulated from each other andindividually connected to corresponding device contact portions atrespective ones of the holes, the device contact portion and the bodycontact portion formed of a material which is both conductive andadhesive.
 13. The device of claim 12, wherein a material, which is bothnonconductive and adhesive, is around the device contact portion and thebody contact portion of the insulation sheet.
 14. The device of claim12, wherein insulation members are around the device contact portion andthe body contact portion, the insulation members are formed of amaterial which is nonconductive and adhesive, and each of the insulationmembers has a thickness less than or equal to one of an adjacent devicecontact portion and an adjacent body contact portion
 15. The device ofclaim 12, further comprising a device holder formed of a nonconductivematerial and holding an edge of a body or a terminal of the biosignalmeasurement device on the top surface of the insulation sheet.
 16. Thedevice of claim 12, wherein the electrode member and the terminal areelectrically connected to each other by surface contact.
 17. Anelectrode for transmission between a biosignal measurement device and aliving body, comprising: a first insulation sheet; at least oneelectrode member formed in a shape of a flat board on a top surface ofthe first insulation sheet, of which one end is formed on the firstinsulation sheet and another end is externally exposed from the firstinsulation sheet and formed of a material which is both conductive andadhesive; and a second insulation sheet provided on the electrodemember, exposing the top surface of the one end of the electrode memberand electrically shutting off the top surface of the another end of theelectrode member.
 18. The electrode of claim 17, wherein a material,which is nonconductive and adhesive, is provided on a bottom surface ofthe insulation sheet and between the at least one electrode member. 19.A biosignal measurement device for making contact with a living body andmeasuring a biosignal, comprising: a signal processing member comprisingan externally exposed snap terminal and a flat board terminal adjacentto the snap terminal; and an electrode member comprising an insulationsheet, a snap contact portion electrically and mechanically connected tothe snap terminal on a top surface of the insulation sheet, a flat boardcontact portion electrically connected to the flat board terminal andformed of a material which is both conductive and adhesive, a first bodycontact portion electrically connected to the snap contact portion on abottom surface of the insulation sheet, and a second body contactportion electrically connected to the flat board contact portion on thebottom surface of the insulation sheet.
 20. The device of claim 19,wherein the signal processing member further comprises an analog signalprocessing unit processing an analog signal transmitted from the snapterminal and the flat board terminal, an A/D signal converter convertingthe analog signal into a digital signal, and a digital signal processingunit processing the converted digital signal.
 21. The device of claim19, wherein the snap contact portion is a protrusion, and the snapterminal is inserted into the snap contact portion to be mechanicallyfixed and electrically connected.
 22. The device of claim 19, whereinthe snap contact portion is rotatably connected to the snap terminal.23. The device of claim 19, wherein the snap contact portion has anoncircular section and maintains a fixed state with respect to the snapterminal.
 24. The device of claim 19, wherein the snap contact portionand the snap terminal have corresponding uneven shapes and aremechanically connected to each other using a magnet.
 25. An electrodefor transmission between a biosignal measurement device and a livingbody, comprising: an insulation sheet; a snap electrode member includinga snap contact portion on a top surface of the insulation sheet and afirst body contact portion electrically connected to the snap contactportion on a bottom surface of the insulation sheet; and a flat boardelectrode member including a flat board contact portion formed of amaterial which is both conductive and adhesive on the top surface of theinsulation sheet and a second body contact portion electricallyconnected to the flat board contact portion on the bottom surface of theinsulation sheet.
 26. The electrode of claim 25, wherein the snapcontact portion is a protrusion.
 27. The electrode of claim 25, whereina portion of the snap contact portion connected to the biosignalmeasurement device has one of a circular section and a noncircularsection.
 28. The electrode of claim 25, wherein the snap contact portionincludes a magnet or a magnetic substance which is adjacent to the snapcontact portion connected to the biosignal measurement device.